1. Technical Field
The present invention relates to document data capturing devices that digitally capture data from both sides of a document, and specifically relates to layout configurations for document data capturing devices furnished with a document conveying mechanism.
2. Description of the Related Art
Conventionally known document data capturing devices that capture data from duplex (two-sided) documents having images formed on both sides include devices furnished with a reversing mechanism for turning documents upside-down, and that after conveying a document to a data-capturing unit to scan one side of the document, turn the document upside down and convey the document to the data-capturing unit again to scan the other side of the document, and devices furnished with a first data-capturing unit for scanning one side of the document, and a second data-capturing unit for scanning the other side of the document, wherein a document is scanned by the first and second data-capturing units.
Document data capturing devices of the latter type are disclosed in, for example, Japanese Unexamined Pat. App. Pub. Nos. H09-46472 and H11-69087. In these document data capturing devices, a first data-capturing unit is provided along an upper side of the document data capturing device body. A second data-capturing unit is provided in a document feeding device hinged onto the document data capturing device body. The second data-capturing unit, provided in the document feeding device, is arranged upstream of the first data-capturing unit and in a vertical conveyance section inside a U-shaped document conveying path. In this configuration, the first and second data-capturing units simultaneously scan the respective sides of a document being conveyed along the conveying path.
In the above-described document data capturing devices, however, a first scanning mechanism, for capturing data from documents passing through the first data-capturing section, is configured with data-capture sensors in a reduction-optics system, while a second scanning mechanism, for capturing data from documents passing through the second data-capturing section, is configured with data-capture sensors in a 1× optics system, as a consequence of which, when both a one side and the other side of a document are printed on a copy sheet, the problem of the tones, contrasts, etc. of the two sides not matching arises. What is more, with the 1× optics data-capture sensors the focal length is short, such that conveying documents within the focal length is extremely problematic. Consequently, in recent years the general practice has been to configure both the first and the second scanning mechanisms with reduction-optics data-capture sensors.
Nevertheless, configuring the first and the second scanning mechanisms both with reduction-optics data-capture sensors entails employing a plurality of mirrors, requiring a lengthy optical pathway, on account of which the issue of the device being scaled up arises. Moreover, the first and the second scanning mechanisms both being configured with reduction-optics data-capture sensors has not in fact meant that the image quality of a print image captured by the first scanning mechanism adequately matches that of a print image captured by the second scanning mechanism.